Return nil when JRuby has no console device

Author: OskarEichler

jruby/lib/io/console/common.rb

@@ -43,6 +43,7 @@ def self.console(sym = nil, *args)
       @console = con
     end
 
+    return nil unless con
     return con.send(sym, *args) if sym
     return con
   end

test/io/console/test_io_console.rb

@@ -720,7 +720,7 @@ def run_noctty(src)
     end
 
     def test_noctty
-      assert_equal(["nil"], run_noctty("IO.console"))
+      assert_equal(["[nil, nil]"], run_noctty("[IO.console, IO.console(:tty?)]"))
       if IO.method_defined?(:ttyname)
         assert_equal(["nil"], run_noctty("STDIN.ttyname rescue $!"))
       end